An ALMA view of CS and SiS around oxygen-rich AGB stars

We aim to determine the distributions of molecular SiS and CS in the circumstellar envelopes of oxygen-rich asymptotic giant branch stars and how these distributions differ between stars that lose mass at different rates. In this study we analyse ALMA observations of SiS and CS emission lines for three oxygen-rich galactic AGB stars: IK Tau, with a moderately high mass-loss rate of $5\times10^{-6}$M$_\odot$ yr$^{-1}$, and W Hya and R Dor with low mass loss rates of $\sim1\times10^{-7}$M$_\odot$ yr$^{-1}$. These molecules are usually more abundant in carbon stars but the high sensitivity of ALMA allows us to detect their faint emission in the low mass-loss rate AGB stars. The high spatial resolution of ALMA also allows us to precisely determine the spatial distribution of these molecules in the circumstellar envelopes. We run radiative transfer models to calculate the molecular abundances and abundance distributions for each star. We find a spread of peak SiS abundances with $\sim10^{-8}$ for R Dor, $\sim10^{-7}$ for W Hya, and $\sim3\times10^{-6}$ for IK Tau relative to H$_2$. We find lower peak CS abundances of $\sim7\times10^{-9}$ for R Dor, $\sim7\times10^{-8}$ for W Hya and $\sim4\times10^{-7}$ for IK Tau, with some stratifications in the abundance distributions. For IK Tau we also calculate abundances for the detected isotopologues: C$^{34}$S, $^{29}$SiS, $^{30}$SiS, Si$^{33}$S, Si$^{34}$S, $^{29}$Si$^{34}$S, and $^{30}$Si$^{34}$S. Overall the isotopic ratios we derive for IK Tau suggest a lower metallicity than solar.Comment: 16 page

The Perils of `Soft' SUSY Breaking

We consider a two dimensional SU(N) gauge theory coupled to an adjoint Majorana fermion, which is known to be supersymmetric for a particular value of fermion mass. We investigate the `soft' supersymmetry breaking of the discrete light cone quantization (DLCQ) of this theory. There are several DLCQ formulations of this theory currently in the literature and they naively appear to behave differently under `soft' supersymmetry breaking at finite resolution. We show that all these formulations nevertheless yield identical bound state masses in the decompactification limit of the light-like circle. Moreover, we are able to show that the supersymmetry-inspired version of DLCQ (so called `SDLCQ') provides the best rate of convergence of DLCQ bound state masses towards the actual continuum values, except possibly near or at the critical fermion mass. In this last case, we discuss improved extrapolation schemes that must supplement the DLCQ algorithm in order to obtain correct continuum bound state masses. Interestingly, when we truncate the Fock space to two particles, the SDLCQ prescription presented here provides a scheme for improving the rate of convergence of the massive t'Hooft model. Thus the supersymmetry-inspired SDLCQ prescription is applicable to theories without supersymmetry.Comment: 11 pages, Latex; 2 figures (EPS); Numerical results extended; conclusions revise

Determining the effects of clumping and porosity on the chemistry in a non-uniform AGB outflow

(abridged) In the inner regions of AGB outflows, several molecules have been detected with abundances much higher than those predicted from thermodynamic equilibrium (TE) chemical models. The presence of the majority of these species can be explained by shock-induced non-TE chemical models, where shocks caused by the pulsating star take the chemistry out of TE in the inner region. Moreover, a non-uniform density structure has been detected in several AGB outflows. A detailed parameter study on the quantitative effects of a non-homogeneous outflow has so far not been performed. We implement a porosity formalism for treating the increased leakage of light associated with radiation transport through a clumpy, porous medium. The effects from the altered UV radiation field penetration on the chemistry, accounting also for the increased reaction rates of two-body processes in the overdense clumps, are examined. We present a parameter study of the effect of clumping and porosity on the chemistry throughout the outflow. Both the higher density within the clumps and the increased UV radiation field penetration have an important impact on the chemistry, as they both alter the chemical pathways. The increased amount of UV radiation in the inner region leads to photodissociation of parent species, releasing the otherwise deficient elements. We find an increased abundance in the inner region of all species not expected to be present assuming TE chemistry, such as HCN in O-rich outflows, H$_2$O in C-rich outflows, and NH$_3$ in both. Outflows whose clumps have a large overdensity and that are very porous to the interstellar UV radiation field yield abundances comparable to those observed in O- and C-rich outflows for most of the unexpected species investigated. The inner wind abundances of H$_2$O in C-rich outflows and of NH$_3$ in O- and C-rich outflows are however underpredicted.Comment: 33 pages, 20 figures, 15 tables, accepted for publication in Astronomy & Astrophysic

Gallic Acid Dimer As a Double π−Hole Donor: Evidence from X‑ray, Theoretical Calculations, and Generalization from the Cambridge Structural Database

In this work, we demonstrate that the centrosymmetric eight-membered supramolecular ring R2 2 (8) that is formed upon dimerization of benzoic acids has a marked tendency to establish π−hole interactions with electron-rich atoms. We have used the Cambridge Structural Database to demonstrate the preference of carboxylic acid dimers to form donor−acceptor interactions involving π−holes located at the C atoms above and below the molecular plane. Moreover, we have carried out DFT calculations (PBE0-D3/def2-TZVP) to investigate the geometric and energetic features of these interactions and how they are affected by the substituents of the aromatic ring. Finally, as an example we report the synthesis and X-ray characterization of a solvate of gallic acid with dioxane, where two molecules of dioxane are located above and below the eight-membered supramolecular ring, forming two symmetrically equivalent O···C π−hole interactions

Methodological quality of network meta-analysis in dentistry : a meta-research

This meta-research aimed to provide an overview of the methodological quality and risk of bias of network meta-analyses (NMA) in dentistry. Searches for NMA of randomized clinical trials with clinical outcomes in dentistry were performed in databases up to January 2022. Two reviewers independently screened titles/ abstracts, selected full texts, and extracted the data. The adherence to PRISMA-NMA reporting guideline, the AMSTAR-2 methodological quality tool, and the ROBIS risk of bias tool were assessed in the studies. Correlation between the PRISMA-NMA adherence and the AMSTAR-2 and ROBIS results was also investigated. Sixty-two NMA studies were included and presented varied methodological quality. According to AMSTAR-2, half of the NMA presented moderate quality (n = 32; 51.6%). The adherence to PRISMA-NMA also varied. Only 36 studies (58.1%) prospectively registered the protocol. Other issues lacking of reporting were data related were data related to the NMA geometry and the assessment of results consistency, and the evaluation of risk of bias across the studies. ROBIS assessment showed a high risk of bias mainly for domains 1 (study eligibility criteria) and 2 (identification and selection of studies). Correlation coefficients between the PRISMA-NMA adherence and the AMSTAR-2 and ROBIS results showed moderate correlation (rho < 0.6). Overall, NMA studies in dentistry were of moderate quality and at high risk of bias in several domains, especially study selection. Future reviews should be better planned and conducted and have higher compliance with reporting and quality assessment tools

Colour-Dielectric Gauge Theory on a Transverse Lattice

We investigate in some detail consequences of the effective colour-dielectric formulation of lattice gauge theory using the light-cone Hamiltonian formalism with a transverse lattice. As a quantitative test of this approach, we have performed extensive analytic and numerical calculations for 2+1-dimensional pure gauge theory in the large N limit. Because of Eguchi-Kawai reduction, one effectively studies a 1+1-dimensional gauge theory coupled to matter in the adjoint representation. We study the structure of coupling constant space for our effective potential by comparing with the physical results available from conventional Euclidean lattice Monte Carlo simulations of this system. In particular, we calculate and measure the scaling behaviour of the entire low-lying glueball spectrum, glueball wavefunctions, string tension, asymptotic density of states, and deconfining temperature. We employ a new hybrid DLCQ/wavefunction basis in our calculations of the light-cone Hamiltonian matrix elements, along with extrapolation in Tamm-Dancoff truncation, significantly reducing numerical errors. Finally we discuss, in light of our results, what further measurements and calculations could be made in order to systematically remove lattice spacing dependence from our effective potential a priori.Comment: 48 pages, Latex, uses macro boxedeps.tex, minor errors corrected in revised versio

Madurella mycetomatis Is Highly Susceptible to Ravuconazole

The current treatment of eumycetoma utilizing ketoconazole is unsatisfactory because of high recurrence rates, which often leads to complications and unnecessary amputations, and its comparatively high cost in endemic areas. Hence, an effective and affordable drug is required to improve therapeutic outcome. E1224 is a potent orally available, broad-spectrum triazole currently being developed for the treatment of Chagas disease. E1224 is a prodrug that is rapidly converted to ravuconazole. Plasma levels of E1224 are low and transient, and its therapeutically active moiety, ravuconazole is therapeutically active. In the present study, the in vitro activity of ravuconazole against Madurella mycetomatis, the most common etiologic agent of eumycetoma, was evaluated and compared to that of ketoconazole and itraconazole. Ravuconazole showed excellent activity with MICs ranging between ≤0.002 and 0.031 μg/ml, which were significantly lower than the MICs reported for ketoconazole and itraconazole. On the basis of our findings, E1224 with its resultant active moiety, ravuconazole, could be an effective and affordable therapeutic option for the treatment of eumycetoma

The SAMI Galaxy Survey: Stellar population radial gradients in early-type galaxies

We study the internal radial gradients of the stellar populations in a sample comprising 522 early-type galaxies (ETGs) from the SAMI (Sydney- AAO Multi-object Integral field spectrograph) Galaxy Survey. We stack the spectra of individual spaxels in radial bins, and derive basic stellar population properties: total metallicity ([Z/H]), [Mg/Fe], [C/Fe] and age. The radial gradient ($\nabla$) and central value of the fits (evaluated at R$_e$/4) are compared against a set of six possible drivers of the trends. We find that velocity dispersion ($\sigma$) - or, equivalently gravitational potential - is the dominant driver of the chemical composition gradients. Surface mass density is also correlated with the trends, especially with stellar age. The decrease of $\nabla$[Mg/Fe] with increasing $\sigma$ is contrasted by a rather shallow dependence of $\nabla$[Z/H] with $\sigma$ (although this radial gradient is overall rather steep). This result, along with a shallow age slope at the massive end, imposes stringent constraints on the progenitors of the populations that contribute to the formation of the outer envelopes of ETGs. The SAMI sample is split between a 'field' sample and a cluster sample. Only weak environment-related differences are found, most notably a stronger dependence of central total metallicity ([Z/H]$_{e4}$) with $\sigma$, along with a marginal trend of $\nabla$[Z/H] to steepen in cluster galaxies, a result that is not followed by [Mg/Fe]. The results presented here serve as constraints on numerical models of the formation and evolution of ETGs.Comment: 14 pages, 9 figures, 3 tables. Submitted to MNRA

Selective blockade of mglu5 metabotropic glutamate receptors is protective against acetaminophen hepatotoxicity in mice

BACKGROUND/AIMS: mGlu5 metabotropic glutamate receptor antagonists protect rat hepatocytes against hypoxic death. Here, we have examined whether mGlu5 receptor antagonists are protective against liver damage induced by oxidative stress. METHODS: Toxicity of isolated hepatocytes was induced by tert-butylhydroperoxide (t-BuOOH) after pretreatment with the mGlu5 receptor antagonists, MPEP, SIB-1757 and SIB-1893. The effect of these drugs was also examined in mice challenged with toxic doses of acetaminophen. RESULTS: Addition of tBuOOH (0.5 mM) to isolated hepatocytes induced cell death (70+/-5% at 3 h). Addition of MPEP or SIB-1893 to hepatocytes reduced both the production of reactive oxygen species (ROS) and cell toxicity induced by t-BuOOH (tBuOOH=70+/-5%; tBuOOH+MPEP=57+/-6%; tBuOOH+SIB-1893=40+/-4%). In mice, a single injection of acetaminophen (300 mg/kg, i.p.) induced centrilobular liver necrosis, which was detectable after 24 h. MPEP (20 mg/kg, i.p.) substantially reduced liver necrosis and the production of ROS, although it did not affect the conversion of acetaminophen into the toxic metabolite, N-acetylbenzoquinoneimine. MPEP, SIB-1893 and SIB-1757 (all at 20 mg/kg, i.p.) also reduced the increased expression and activity of liver iNOS induced by acetaminophen. CONCLUSIONS: We conclude that pharmacological blockade of mGlu5 receptors might represent a novel target for the treatment of drug-induced liver damage